Method of making grooved sleeves



Dec. 25, 1934. H. LAMPART METHOD OF MAKING GROOVED SLEEVES Filed Dec. 14, 1931 Jiyz AF/IHN .f ,Zvw @Lw v i l 0 W. y

Patented Dee. 25, 1934 1,985,833 METHOD 0F MAKING GROOVED SLEEVES Hugo Lampart, Baden, Germany, assignor 'to Berlin-Karlsruher `Industrie-Werke A.

Karlsruhe, (.lcrmany Application December 14. 1931, serial No.l 581,046

In Germany December Z0, 1930 1 claim. (c1. aos- 8) This invention relates to a method for the-pr9 duction of helical longitudinal grooves on the outer surface of cylindrical tubes, more particularly spinning bobbins for the artificial silk industry.

As compared, for example, with a rolling proc-j ess,V there is obtained by the method according to the invention the advantage of very simple production, as this process may immediately follow the usual drawing process for producing the sleeve, i. e., constitute a continuation thereof, so

that the general production is one of a uniformv nature.

In producingV the body of thespool or'sleeve it` is possible to draw a plurality of sleeves simultaneously inone piece, the single sleeves being cut therefrom in therequisite length. This operation may be followed in-a very simple manner by the method of producing the grooves in accordance with the invention.

A possible form of embodiment of the appa-J' ratus vfor carryingthe invention into effect, is illlustrated in the accompanying drawing.

Fig. 1 shows, in longitudinal section, an apparatus for producing sleeves,which are grooved on the outside and smooth onthe interior;

Fig. 2 is a cross-sectional view of a sleeve or ALetters Patent is:

spool produced according tothe invention by the apparatus.` v

With the apparatus ac'cordlng to Fig. l there are produced sleeves or spools which are smooth o n the inside but furnished withV a corrugated or grooved exterior as in Fig. 2. The mandrel 10 is mounted in thrust bearings 2 and 4 in a member' 1 which is firmly secured against rotation but is displaceable in the direction of the axis. The mandrel or core is forced through, astation 'ary drawing ring 'I surrounding the same, which ring, for the production of sleeves according to Fig.- 2, is provided with ribs conforming'with` the .helicaliy disposed grooves to be produced and acts as a matrix.

What I claim as new and desire to secure by A method for producing spinning bobbins par-- ticularly-for the artificial silk industry comprising placing a cylindrical tube having a smooth 2o inner wall on a smooth and' axially f repely-rotatable mandrel and forcing the tube through a draw ring having internal helical ribs to form helical longitudinal grooves on the outer wall of the tube. A HUGO LAMPARl. 

